The problem with soundcloud...
 

Not sure what group this belongs best to, but I suspect it'll be most understood by those of us interested in recording...

Just saw something very enlightening. I was looking at a track Barry posted using soundcloud using the spectral view in iZotope RX. And it looked rather odd. So I did a quick exercise to see just how much soundcloud's streaming mucks with the sound quality. I took the first few seconds of a demo I posted a few days ago and compared what the spectrum view looks like of my original vs what comes back from soundcloud. Hope you can see this with an embedded image.

Here's my local, original track:

Attachment 68618

If you don't know RX, what this shows is time on the X axis, frequency, 0 to 20KHz on the Y axis, and color is intensity or volume. This is just the left track. The sort of vertical stronger lines represent the attack of notes, and you can see the tails of the notes as they decay.

Now here's what comes back from soundcloud for that same few seconds:

Attachment 68617

it's hard to see the detail in what's getting posted here, but look closely. Everything's cut off the extreme highs, no surprise - that's at about 15K. Not a huge deal, there's not a lot there, and you might not hear it anyway. But what's striking - and probably more so if you could see the full-resolution image is how frequencies and intensities are mangled across the board. It's like looking at a low resolution image that's all pixellated. The decay of notes in my original look nice and smooth, soundcloud's version has little holes everywhere. The transients are all smeared. What a mess....

I always try to make sure anything I post is also downloadable, which I believe gives you the original file (I guess I should verify that). Soundcloud's certainly convenient because we can embed it here and it's quick and easy to play a track in a post. But, clearly that convenience is coming with substantial cost. I knew it didn't sound as good, but even with that, this amount of file damage surprised me. Probably shouldn't have, but...

Does anyone have an idea for an alternative? Is this why some people use YouTube?

Doug,

I’m glad you confirmed what my ears always hear. Thanks for sharing this.

Doug, that's really insightful visual example of an audio problem, and one that was instantly recognizable to me as an RX user. Thanks for posting and for the soundcloud caveat.

youtube mooshes everything down too.

-Mike

I remember watching a video about a loudness meter plugin that optimized a track for various platforms. They had a few examples of of minimizing the effects by keeping the LUFS at a certain point and limiting the peaks to minimize the effect of the streaming algorithms "correction". Not sure if that would help in the above example? I'll see if I can find that video and post it here.

EDIT: I couldn't find the video, but I did find this:

"Although there is no absolute loudness to which you should master your track, a great range when mastering for Soundcloud is -18 LUFS to -10 LUFS. Keep in mind that Soundcloud will normalize your track to -14 LUFS, so keeping the loudness around this figure will work well."

Also, on this page, they do offer a high quality streaming service, although I'm sure you'd have to pay something for it:

https://help.soundcloud.com/hc/en-us...lity-streaming

Couple thoughts and question
Question -Doug when you say "comes back from SoundCloud" can we assume you mean the realtime compressed streaming file

Yes all the small rectangle looking holes in the SC would seem to probably make the sound less smooth and more distorted (how much and if we would notice it is the question) But it has always seemed to me that SC streaming can get more distorted more quickly particularly in the highs compared to listening back on my system to the original WAV file.
I think Sound Cloud has switched to ACC 256 which is better IMO than the 128 bit they used to do But it seems still not up to uncompressed as per Dougs example .

Yes the Nugen MasterCheck plug in I use has settings for specific streaming platforms for example I think YouTube wants to see -14 to -12 LUFS max over that it will automatically reduce it
here is an excerpt from the Master Check web page

"Playout services essentially have a ‘letter box’ through which they deliver your audio; if it doesn’t slide through then the service will force it to fit. A super-loud master might win the loudness war on CD, but will simply be turned down on any major streaming service. This leaves valuable headroom which you could have used for transient detail and punch.

It is important to be aware of how True Peak clipping can cause downstream distortion in encoded audio. Heavy compression will result in audible 'fizzing' and loss of stereo definition, especially with lower quality codecs."

I had noticed that the differences in my recordings i.e. using large condensers vs small condensers, sort of faded away once I uploaded to SC.

My Reaper "Render to File" settings are:

Sample Rate: 44,100
Channels: Stereo
Resample mode : Sinc Interpolation 384Pt without any normalization
WAV bit depth: 24 bit PCM


I wonder if there is another public sharing site and if it even matters. They all must do some sort of file limiting.

When I posted things on Spotify, I was testing it out and after a time I felt that listening to Spotify slightly improved my sound. Went back and forth from Soundcloud.
I googled it, and sure enough they have info that I believe verifies this! And if you're at a higher level of membership in Spotify, they enhance this a bit further.
I was pleased that my ears didn't lie to me! LOL!

Maybe I missed it did you post WAVs to SC? What was the LUFS?

If you pay for premium SC service (whatever they call it), people can download the same files (WAV?) you uploaded, if you don't pay for premium, they can only download the SC-compressed file.

Thanks Mike,...interesting.
My SC is the "Pro", so it's above basic and below premium (good enough for me at this time!). Nearly All files are WAV and are mixed/mastered professionally and are at "commercial levels" when uploaded.

Soundcloud does mangle the uploaded audio file quite audibly. I have noticed that I get a better sounding file on SC if I upload a Wave file. If I upload an mp3 file the SC result is really horrible.

- Glenn

Yes as as I noted SC now streams in AAC 256, so if you upload an MP3 it gets encoded twice

Yes, I posted a wav file, 24 bits, 44.1 (this was from the guitar comparison I posted a few days ago). LUFS for that track was -15.7. I suppose some of this could be from loudness normalization - tho it does not appear to me that they brought this track up to -14, but I suspect that it is more from the compression/bit-rate reduction.

I know we'd get something like this just from looking at mp3 vs wav, and that other services will have similar issues. The one that sounds noticeable worse to me is Spotify. But I was just surprised by the extent of the damage and that it was so clearly displayed by the visual.

Yes, I was capturing what was streamed.

There was no clipping or overs on my example. True Peak is -2db.